Introduction

I have been monitoring honey bee health in Maritime Canada and
internationally since 2001 for various contracts and for my PhD thesis. 
Also, I have been using colony assessment data and provisional thresholds to
make survival predictions since 2003.  Therefore, I offer the following
facts, experiences and opinions as a contribution to understanding honey bee
losses.

Maritime Canada winter loss reports as of April 12/07

New Brunswick
	•	At least two cases of 70-80% losses over winter
	•	One beekeeper claimed sudden loss of adult bee population in some hives
in fall of 2006.  He feels it is similar to CCD, but this has yet to be
determined.
	•	In the above case, it was reported that VM was not as abundant as in some
previous years, but no quantitative data available because no monitoring was
done.

Prince Edward Island
	•	An early report from one beekeeper who suffered a 60-70% loss; actual
overall average losses for the province will not be known for a few weeks yet.
	•	Based on the results of monitoring, the survival prediction for 05/06 was
25-55% mortality over winter (officially reported loss in spring '06 was
38%), and for 06/07 it is 55-75% mortality (official report pending).
	•	AFB epidemic and some samples confirmed resistant
	•	VM susceptibility to fluvalinate decreased over previous year

Nova Scotia
	•	At least three reports of 70-80% losses; other reports variable,
preliminary and unconfirmed.
	•	I visited an apiary of 70 hives and estimated a minimum of 70% losses
	•	AFB resistance confirmed in some samples.

Other facts (general notes with no specific location information for reasons
of confidentiality)
	•	Nosema in 2007 spring bee samples (live collected bees) = 0.5 to 12
million spores per bee.
	•	In some summer collected bees in 2006 levels of Nosema over 6 million
spores per bee.
	•	Species of Nosema was not determined in any cases.
	•	100% of colonies in one study with mean tracheal mite infection rate of
10% with rates as high as 20%, all in summer bees.
	•	Overall mean number of VM/100 bees from all studies roughly 9 mites
(based on alcohol wash method).  Lethal threshold considered to be >8. 
Counts much higher in many cases.
	•	Deformed-wing virus (DWV) accounted for 20% of bee mortality in one study
and DWV recorded from an increasing number of colonies in both the US and
Canada.
	•	More black bees, bald-brood, K-wing observed than ever before.
	•	Small hive beetle range expanding.  The beetle is nasty by itself, but
desperation treatments may be contributing to toxic effects to bees and brood.
	•	Even when no traditional diseases present (AFB, EFB, sacbrood) hives
weakened by chalkbrood, mites, Nosema, viruses, nutritional deficiencies.
	•	Effects of beekeeper applied concoctions not clear, however, MOST
beekeepers experiment with products and even apply off-label treatments.
	•	Residues of plant protection products (PPP) have only been found in a few
cases in Maritime Canada and linked to bee losses in only one case over the
three year period of studies.
	•	The symptom of "a queen and a handful of workers" remaining in a colony
was observed in the one case linked to a PPP (a.i. phosmet) back in 2002
(pictures available).  Therefore, this symptom is not new.  Can it have
other causes?  I have not seen a similar situation caused by other factors
other than hives abandoned by absconding VM infested bees.
	•	Survival prediction analysis based on colony assessment data from studies
in the US forecast potential colony losses by spring 2007 to be in the range
of 70-100% in some apiaries.
	•	The factors responsible for the prediction of substantial colony losses
are different combinations of disorders and stressors.  Because there is no
single agent at work, the cause of losses is referred to as Multiple &
Various Causative Agents Syndrome (MVCAS).
	•	I have detected what I believe to be the lengthening of worker brood
development time by as much as 2-3 days in colonies heavily infested with VM
and DWV.  The colonies had also been treated with off-label products for
mite control.  Could there be some kind of interaction or reaction to stress
taking place?  How would a lengthened honey bee brood cycle affect VM
development?  A logical possibility is that it would increase the number of
mites that successfully emerge from the worker cells as adults.  VM natural
drop in these hives increased by an average of 245% over three weeks.  These
observations are preliminary and need to be verified by further research.  

Conclusions (or opinions, if you prefer)
	•	To understand bee health requires thorough, comprehensive antemortem
colony assessments.
	•	Survival over winter can be predicted when adequate quantitative
monitoring data is available to compare to provisional thresholds, and when
interactions are considered.
	•	If honey bee health continues to decline annually, the time is near when
honey bees will not be able to survive without being managed.
	•	Managed bees will only survive if pest management can be improved (i.e.
more efficient and effective).


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